..Unlike other mature lineages, mast cell survival is dependent on KIT and the presence of these two activating mutations may have a greater impact on the expansion of this cell compartment and in resultant disease severity...

..Mastocytosis associated with germline KIT activating mutations is exceedingly rare. We report the unique clinicopathologic features of a patient with systemic mastocytosis caused by a de novo germline KIT K509I mutation...

..Thus, Pten deletion in the mast cell compartment results in a mast cell proliferative phenotype in mice, demonstrating that dysregulation of PI3K signals is vital to the observed mast cell hyperplasia...

..This has directly translated into the development of novel targeted therapies. These therapies hold great promise to patients and health care providers that a "cure" for systemic mastocytosis may someday be obtainable...